At one of the “closed” tunnels at power up (gargantua part, to be specific) The world isn’t sealed. It’s the door that would open later due to a trigger (i think).
So yeah, map leak. I’ll try and get a screenshot later, but i’m a bit busy right now. Unless someone else can be bothered to go look for it? It’s not really effecting gameplay, but might affect performance for low-powered machines.